Upward discharge waste devices are known. For example, an upward discharge waste device is supplied by AKW Medi-Care of Worcester, United Kingdom. This type of waste is fastened to a wall of a sump on a shower tray and provides means whereby waste water entering the sump may be pumped out generally in an initially vertically upwards direction. The waste device comprises a hollow housing of substantially uniform cross-sectional shape, generally being cuboid. To allow the pumped suction to remove as much waste water from the sump as possible, the housing is closely spaced from the bottom of the sump. Waste water flowing into the sump must therefore enter the hollow housing from under its lower edge. As the water level in the housing rises, the waste water outlet is reached and the waste water is drawn through the waste water outlet by a pump connected to the drain.
Another example of an upward discharge device is also known from Impey UK Ltd, where the discharge channel connected to the pump is a tube located in the top of a waste sump cover, and the waste liquid is drawn directly from the sump through the pipe by the pump. The pipe end is similarly closely spaced from the bottom of the sump to remove as much waste water as possible. Again, however, the discharge housing within the sump is of uniform cross-sectional shape, being cylindrical.
These types of known arrangements are intended to provide a means of removing waste water from a shower drain sump in installations where it is not possible to create piped arrangements below the level of the shower base—such as multi-occupancy ‘high-rise’ buildings where floors are reinforced concrete and may not be breached for various reasons. Often in such installations, a communal service duct runs vertically through the bathroom linking one floor to another and providing a common means to route power and other services, including waste water disposal, too and from the building. In such installations, the shower waste must be directed into the waste pipe from a position above the floor level in the accommodation.
However, since waste water may only flow into the sump at a relatively low and erratic flow rate, dictated by movements of the person showering, the placement of their feet obstructing water drainage to the waste sump, the effects of gravity, and the slope of the shower flooring, for example, it is quickly drawn out through the relatively small effective diameter of the waste water outlet by the uniform action of the pump. Consequently, a substantial amount of air is also entrained, causing substantial and undesirable noise.
The present invention seeks to overcome this problem.